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The exploration of new application forms of covalent organic frameworks (COFs) in Li-S batteries that can overcome drawbacks like low conductivity or high loading when typically applied as sulfur host materials (mostly ≈20 to ≈40â wt % loading in cathode) is desirable to maximize their low-density advantage to obtain lightweight, portable, or high-energy-density devices. Here, we establish that COFs could have implications as microadditives of binders (≈1â wt % in cathode), and a series of anthraquinone-COF based hollow tubes have been prepared as model microadditives. The microadditives can strengthen the basic properties of the binder and spontaneously immobilize and catalytically convert lithium polysulfides, as proved by density functional calculations, thus showing almost doubly enhanced reversible capacity compared with that of the bare electrode.
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The exploration of novel systems for the electrochemical CO2 reduction reaction (CO2 RR) for the production of hydrocarbons like CH4 remains a giant challenge. Well-designed electrocatalysts with advantages like proton generation/transferring and intermediate-fixating for efficient CO2 RR are much preferred yet largely unexplored. In this work, a kind of Cu-porphyrin-based large-scale (≈1.5â µm) and ultrathin nanosheet (≈5â nm) has been successfully applied in electrochemical CO2 RR. It exhibits a superior FE CH 4 of 70 % with a high current density (-183.0â mA cm-2 ) at -1.6â V under rarely reported neutral conditions and maintains FE CH 4 >51 % over a wide potential range (-1.5 to -1.7â V) in a flow cell. The high performance can be attributed to the construction of numerous hydrogen-bonding networks through the integration of diaminotriazine with Cu-porphyrin, which is beneficial for proton migration and intermediate stabilization, as supported by DFT calculations. This work paves a new way in exploring hydrogen-bonding-based materials as efficient CO2 RR catalysts.
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Multidimensional fabrication of metal-organic frameworks (MOFs) into multilevel channel integrated devices are in high demanded for Li-S separators. Such separators have advantages in pore-engineering that might fulfill requirements such as intercepting the diffusing polysulfides and improving the Li+ /electrolyte transfer in Li-S batteries. However, most reported works focus on the roles of MOFs as ionic sieves for polysulfides while offering limited investigation on the tuning of Li+ transfer across the separators. A photoinduced heat-assisted processing strategy is proposed to fabricate MOFs into multidimensional devices (e.g., hollow/Janus fibers, double-or triple-layer membranes). For the first time, a triple-layer separator with stepped-channels has been designed and demonstrated as a powerful separator with outstanding specific capacity (1365.0â mAh g-1 ) and cycling performance (0.03 % fading per cycle from 100th to 700th cycle), which is superior to single/double-layer and commercial separators. The findings may expedite the development of MOF-based membranes and extend the scope of MOFs in energy-storage technologies.
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OBJECTIVE: To compare the effectiveness of lung isolation among double-lumen endotracheal tube, Univent blocker and bronchial blocker during thoracic surgical anesthesia. METHODS: A total of 120 patients undergoing elective thoracic surgery were enrolled. They were intubated with Mallinckrodt DLT (DLT group, n = 40), Univent blocker (UNI group, n = 40) and Coopdech bronchial blocker (BB group, n = 40) after intravenous anesthesia induction. The following parameters were recorded:(1) time to initially position the assigned tube; (2) changes of mean arterial pressure (MAP) and heart rate (HR) at 5 min post-intubation; (3) lung collapse scores; (4) frequency of malpositions; (5) airway press and blood gas change during one lung ventilation (OLV); (6)postoperative sore throat at 24 h postoperation. RESULTS: No statistical difference existed in positioning three types of endotracheal tubes. But MAP and HR were higher at post-intubation in DLT group compared with the other 2 groups. No difference existed among the lung isolation devices in lung collapse scores at 5/10 min after pleural opening. As compared with the UNI and BB groups, Ppeak and Pplat increased while compliance decreased in DLT group during OLV. Statistical differences existed in tube malpositions among three groups (n = 4, DLT; n = 5, UNI; n = 8, BB). The incidence of postoperative sore throat was significantly higher in DLT group (70%) than the other two groups (37.5%, UNI; 22.5%, BB). CONCLUSION: As compared with DLT, Univent and Coopdech bronchial blocker may reduce the airway injury and improve the compliance during OLV. But there is a higher intraoperative incidence of tube malposition.
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Intubación Intratraqueal/métodos , Ventilación Unipulmonar/métodos , Procedimientos Quirúrgicos Torácicos/métodos , Secuestro Broncopulmonar/cirugía , Femenino , Humanos , MasculinoRESUMEN
Photocatalytic CO2 reduction reaction has been developed as an effective strategy to convert CO2 into reusable chemicals. However, the reduction products of this reaction are often of low utilization value. Herein, we effectively connect photocatalytic CO2 reduction and amino carbonylation reactions in series to reconvert inexpensive photoreduction product CO into value-added and easily isolated fine chemicals. In this tandem transformation system, we synthesize an efficient photocatalyst, NNU-55-Ni, which is transformed into nanosheets (NNU-55-Ni-NS) in situ to improve the photocatalytic CO2-to-CO activity significantly. After that, CO serving as reactant is further reconverted into organic molecules through the coupled carbonylation reactions. Especially in the carbonylation reaction of diethyltoluamide synthesis, CO conversion reaches up to 85%. Meanwhile, this tandem transformation also provides a simple and low-cost method for the 13C isotopically labeled organic molecules. This work represents an important and feasible pathway for the subsequent separation and application of CO2 photoreduction product.
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OBJECTIVE: We investigated the effect of dexmedetomidine anesthesia on postoperative cognitive function after pulmonary surgery. METHODS: A blinded, prospective, randomized, placebo-controlled study was performed on 60 patients (age range 65-74 years) undergoing lobectomy by video-assisted thoracoscopic surgery (29 in the dexmedetomidine group; 31 in the placebo group). Dexmedetomidine group patients received dexmedetomidine, and placebo group patients received an equal volume of physiological saline 20 minutes before anesthesia induction. Cognitive function was evaluated using the Montreal Cognitive Assessment 1 day before surgery and on postoperative day (POD)1, POD3, and POD7. The regional cerebral oxygen saturation (rSO2) was monitored continuously by near-infrared spectroscopy before anesthesia. RESULTS: The Montreal Cognitive Assessment score was significantly different between the two groups on POD1 (dexmedetomidine 26.4 ± 0.73 vs. placebo 25.5 ± 0.96) and POD3 (dexmedetomidine 27.1 ± 0.79 vs. placebo 26.6 ± 0.80). Specifically, attention and orientation scores were increased in the dexmedetomidine group on POD1 and POD3. The rSO2 was not significantly different between the dexmedetomidine and placebo groups. CONCLUSION: Dexmedetomidine given before induction of anesthesia could reduce the risk of postoperative cognitive dysfunction and might not decrease rSO2. Hence, dexmedetomidine could be employed in pulmonary surgical procedures, especially for older patients with a high risk of cognitive dysfunction.
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Dexmedetomidina , Procedimientos Quirúrgicos Pulmonares , Anciano , Anestesia General , Humanos , Pruebas de Estado Mental y Demencia , Estudios ProspectivosRESUMEN
The design of selective and efficient covalent organic frameworks (COFs) based electrocatalysts with tunable morphology for efficient CO2 reduction reaction (CO2RR) to CH4 is highly desirable. Here, two kinds of anthraquinone-based COFs (i.e., AAn-COF and OH-AAn-COF) with tunable 1D superstructures (e.g., nanofibers (NF) and hollow tubes (HT)) have been produced via Schiff-base condensation reaction. Interestingly, a rarely reported nanosheet-based self-template mechanism and a nanosheet-crimping mechanism have been demonstrated for the production of COF-based nanofibers and hollow tubes, respectively. Besides, the obtained COF-based superstructures can be post-modified with transition metals for efficient CO2RR. Specifically, AAn-COF-Cu (NF) and OH-AAn-COF-Cu (HT) exhibit superior faradaic-efficiency with CH4 (FECH4) of 77% (-128.1 mA cm-2, -0.9 V) and 61% (-99.5 mA cm-2, -1.0 V) in a flow-cell, respectively. Noteworthy, the achieved FECH4 of AAn-COF-Cu (NF) (77%) the is highest one among reported crystalline COFs. This work provides a general methodology in exploring morphology-controlled COFs for electrocatalytic CO2RR.
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The sluggish kinetics and unclear mechanism have significantly hindered the development of Li-CO2 batteries. Here, a Li-CO2 battery cathode catalyst based on a porphyrin-based covalent organic framework (TTCOF-Mn) with single metal sites is reported to reveal intrinsic catalytic sites of aprotic CO2 conversion from the molecular level. The battery with TTCOF-Mn exhibits a low overpotential of 1.07 V at 100 mA/g as well as excellent stability at 300 mA/g, which is one of the best Li-CO2 battery cathode catalysts to date. The unique features of TTCOF-Mn including uniform single-Mn(II)-sites, fast Li+ transfer pathways, and high electron transfer efficiency contribute to effective CO2 reduction and Li2CO3 decomposition in the Li-CO2 system. Density functional theory calculations reveal that different metalloporphyrin sites lead to different reaction pathways. The single-Mn(II) sites in TTCOF-Mn can activate CO2 and achieve an efficient four-electron CO2 conversion pathway. It is the first example to reveal the catalytic active sites and clear reaction pathways in aprotic Li-CO2 batteries.
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Metal-organic framework (MOF) based mixed matrix membranes (MMMs) have received significant attention in applications such as gas separation, sensing, and energy storage. However, the mass production of MOF-based MMMs with retained porosity remains a longstanding challenge. Herein, an in situ heat-assisted solvent-evaporation method is described to facilely produce MOF-based MMMs. This method can be extended into various MOFs and polymers with minimum reaction time of 5 min. Thus-obtained MMMs with high uniformity, excellent robustness, well-tuned loading, and thickness can be massively produced in industrial-level efficiency (≈4 m in a batch experiment). Furthermore, they can be readily applied as powerful separators for Li-S cell with high specific capacity (1163.7 mAh g-1) and a capacity retention of 500.7 mAh g-1 after 700 cycles at 0.5 C (0.08% fading per cycle). This work may overcome the longstanding challenge of processing MOFs into MMMs and largely facilitate the industrialization process of MOFs.
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Electrochemical CO2 reduction reaction (CO2RR) to formate is economically viable considering the energy input and market value. Through learning nature, a series of chloroplast-like porous bismuth-based core-shell (CPBC) materials have been designed. In these materials, the porous carbon can enrich and transfer CO2 to the core-shell Bi@Bi2O3 in CO2 reduction process, during which Bi2O3 layer can be transformed into activated metastable layer to efficiently convert CO2 into formate and Bi can provide abundant electrons. Based on this, superior performances for most of important parameters in CO2RR can be achieved and best of them, CPBC-1 presents remarkable Faradaic efficiency (FEformate > 94%) over a wide potential range (-0.65 to -1.0 V) with high catalysis durability (>72 h). Noteworthy, its maximum energy efficiency is as high as 76.7% at -0.7 V, the highest one in reported bismuth-based materials. This work opens novel perspectives in designing nature-inspired CO2RR electrocatalysts.
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BACKGROUND: The present study aims to evaluate the influence of alveolar recruitment strategy (ARS) and positive end-expiratory pressure (PEEP) combined with autoflow on respiratory mechanics, the oxygen index (OI), pulmonary shut [Qs/Qt(%)], and the concentrations of IL-6 and TNF-α in venous blood after surgery in obese patients who experienced thoracic surgery with one-lung ventilation (OLV). METHODS: A total of 36 obese patients with ASAII-III degree, who experienced selective pulmonary lobectomy, were within 36-74 years old, and had a BMI of 30-40 kg/m2, were randomly divided into two groups: control group (C group) and protective ventilation group (P group). In the P group, ARS was given once when OLV began. Then, ventilation at 7 mmHg of PEEP and autoflow were given. The Ppeak before OLV (T1), at 30 minutes after OLV (T2), and at the 5 minutes after two-lung ventilation (TLV) (T3), and the changes of Pplat and Cdyn were recorded. Then, arteriovenous blood was drawn at T1, T2, T3 and T4 (6 hours after the operation), blood-gas indicators, including SPO2, PaCO2 and PaO2, were measured, and the value of Qs/Qt(%) was calculated. Afterwards, venous blood was collected at T1 and T5 (18 hours after surgery), and the concentrations of IL-6 and TNF-α were detected. The clinical pulmonary infection score (CPIS) was determined at the first day and seventh day after the operation. RESULTS: In both groups, Cdyn and OI decreased, while Pplat, Ppeak and Qs/Qt(%) increased (P<0.05) at T2, when compared with those at T1. At T2 and T3, Pplat and Ppeak decreased (P<0.05) in the P group, when compared with the C group. At T2, T3 and T4, OI increased (P<0.05) in the P group, when compared with the C group. At T2, T3 and T4, PaCO2 and Qs/Qt(%) decreased in the P group, when compared with the C group. The concentrations of IL-6 and TNF-α decreased in the P group, when compared with the C group. CONCLUSIONS: The ventilation model of ARS and PEEP combined with autoflow can better reduce airway pressure and the production of injurious inflammatory cytokines in blood in obese patients. Furthermore, it can reduce Qs/Qt during and at 6 hours after thoracotomy, improve OI and maintain the acid-base balance of the internal environment, which may be applied in clinical work. This brings new enlightenment and needs to be clarified through further studies.
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BACKGROUND: The important role of angiogenesis displaying in tumor development and metastasis has been generally realized. Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and endostatin (ES) are critical members of angiogenesis modulating the balance between pro-angiogenenic and anti-angiogenenic factors. The aim of this study was to evaluate the circulating level of these factors in serum and explore their prognostic significance in 96 operable non-small cell lung cancer (NSCLC) patients. METHODS: Pre-operational serum VEGF, bFGF, and ES were determined by commercially available enzyme-link immunosorbent assay for 96 NSCLC patients and compared to a cohort of healthy controls (n = 51). Values were correlated with clinicopathological features and overall survival (OS). RESULTS: The pretreatment serum levels of VEGF, bFGF and ES in NSCLC were significantly higher than in the healthy control (P < 0.001, P = 0.009 and P = 0.016, respectively). Univariate survival analysis showed that a high bFGF level correlated with shorter OS and remained an independent factor in multivariate analysis (hazard ratio [HR] = 1.918, 95% confidence interval [CI], 1.061-3.464). In the squamous subtype, a high bFGF indicated a particularly poor prognosis (HR = 2.609, 95% CI, 1.188-5.729). CONCLUSIONS: bFGF is an independent predictor of poor survival in patients with NSCLC. For patients with high serum bFGF, aggressive antitumor treatments should be given after surgery. Approaches targeting the bFGF signaling pathway should be considered as potentially promising therapeutic strategies in NSCLC, especially for the squamous subtype.